FIG. 7.

The high-glucose-induced Ca²⁺ increase and ERK1/2 activation lead to mitochondrial fragmentation and the ROS increase. (A) Cell counting revealing a reduction of the high-glucose-induced mitochondrial fragmentation upon inhibition of the ERK1/2 activation. Error bars represent SEM. *p < 0.05. (B) ROS, assessed by dihydroethidium fluorescence, in H9c2 cells demonstrated that PD98059, but not KN-93, decreased the high-glucose-induced ROS increase, indicating the necessary role of the ERK1/2 activation in this process. ROS was measured at 15 min in high-glucose incubation (HG). NG, normal glucose incubation. Error bars represent SEM. *p < 0.05. (C) The sequence of events leading to the ROS increase in high-glucose stimulation.